數學暑期功課 急!!!

1.
6ax + 4bx - 2cx - 3ay - 2by + cy
= (6ax + 4bx - 2cx) - (3ay + 2by - cy)
= 2x(3a + 2b - c) - y(3a + 2b - c)
= (2x - y)(3a + 2b - c)


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2.
(b - 1)² - 10(b - 1) + 25
= (b - 1)² - 2(b - 1)(5) + (5)²
= [(b - 1) - 5]²
= (b - 6)²


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3.
6p² + 19p - 7
= (2p + 7)(3p - 1)


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4.
6b² - (17/2)b + 3
= (1/2)(12b² - 17 + 6)
= (1/2)(4b - 3)(3b - 2)


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5.
20x² + 44xy - 15y²
= (10x - 3y)(2x + 5y)


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6.
-6m² + 46mn -60n^2
= -2(3m² - 23mn + 30n²)
= -2(m - 6n)(3m - 5n)


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7.
(2a + b)(2a - b) - 4a + 1
= [(2a)² - b²] - 4a + 1
= 4a² - b² - 4a + 1
= (4a² - 4a + 1) - b²
= [(2a)² - 2(2a)(1) + (1)]² - b²
= (2a - 1)² - b²
= (2a - 1 + b)(2a - 1 - b)
= (2a + b - 1)(2a - b - 1)


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8.
a³ + b³ - a²b - ab²
= (a³ - a²b) - (ab² - b³)
= a²(a - b) - b²(a - b)
= (a² - b²)(a - b)
= (a + b)(a - b)²